精馏塔的工艺计算

.word教育资料2精馏塔的工艺计算2.1精馏塔的物料衡算2.1.1基础数据（一）生产能力：10万吨/年，工作日330天，每天按24小时计时。（二）进料组成：乙苯212.6868Kmol/h；苯3.5448Kmol/h；甲苯10.6343Kmol/h。（三）分离要求：馏出液中乙苯量不大于0.01，釜液中甲苯量不大于0.005。2.1.2物料衡算（清晰分割）以甲苯为轻关键组分，乙苯为重关键组分，苯为非轻关键组分。01.0DHKx，005.0WLKx，表2.1进料和各组分条件由《分离工程》P65式3-23得：,1,,1LKiLKWiHKDLKWzxDFxx（式2.1）2434.13005.001.01005.0046875.0015625.08659.226DKmol/hW=F-D=226.8659-13.2434=213.6225Kmol/h0681.1005.06225.21322WXW，Kmol/h编号组分if/kmol/hif/%1苯3.54481.56252甲苯10.63434.68753乙苯212.686893.7500总计226.8659100.word教育资料5662.90681.16343.10222fdKmol/h132434.001.02434.1333DXDd，Kmol/h5544.212132434.06868.212333dfKmol/h表2-2物料衡算表2.2精馏塔工艺计算2.2.1操作条件的确定一、塔顶温度纯物质饱和蒸气压关联式（化工热力学P199）：CCSTTxDxCxBxAxxPP/1)()1()/ln(635.11表2-3物性参数注：压力单位0.1Mpa，温度单位K编号组分if/kmol/h馏出液id釜液i1苯3.54483.544802甲苯10.63439.56621.06813乙苯212.68680.1324212.5544总计226.865913.2434213.6225组份相对分子质量临界温度CT临界压力CP苯78562.248.9甲苯92591.841.0乙苯106617.236.0名称ABCD.word教育资料表2-3饱和蒸汽压关联式数据以苯为例，434.02.562/15.3181/1CTTx1.5)434.033399.3434.062863.2434.033213.1434.098273.6()434.01()(635.11CSPPIn01.02974.09.48)1.5exp(aSPMPaP同理，可得MPaPb1.00985.00露点方程：niiippy101，试差法求塔顶温度表2-4试差法结果统计故塔顶温度=105.5℃二、塔顶压力塔顶压力Mpap1.0013.1顶三、塔底温度苯-6.982731.33213-2.62863-3.33399甲苯-7.286071.38091-2.83433-2.79168乙苯-7.486451.45488-3.37538-2.23048t80.085.0100105.51060ap1.00801.17291.79612.07942.10670bp0.38710.45870.73940.87120.88400cp0.16720.20170.34170.40950.4161等式左边2.18711.84881.52980.98040.9664等式右边0.98690.98690.98690.98690.9869.word教育资料泡点方程：pxpniii10试差法求塔底温度故塔底温度=136℃四、塔底压力塔底压力Mpap1.0013.1底五、进料温度进料压力为Mpap1.0013.1进，泡点方程：pxpniii10试差法求进料温度故进料温度=133℃六、相对挥发度的计算据化学化工物性数据手册，用内插法求得各个数据5.105顶t℃，961.5苯514.2甲苯1乙苯；t1001101301351360bp0.73940.99221.69871.92491.97280cp0.34170.47260.85390.97951.0063等式左边0.34370.47510.85800.98411.0110等式右边1.01331.01331.01331.01331.0133t1001101301321330ap1.79612.33573.77773.95214.04150bp0.73940.99221.69871.78661.83180cp0.34170.47260.85390.90250.9276等式左边0.38310.52600.93920.99161.0186等式右边1.01331.01331.01331.01331.0133.word教育资料136底t℃，96.1甲苯1乙苯；133进t℃，38.4苯97.1甲苯1乙苯综上，各个组份挥发度见下表据清晰分割结果，计算最少平衡级数。26.6148.2lg)1324.05544.2120681.15612.9lg(lg))()lg((minHKLKWLKHKDHKLKxxxxN2.2.2塔板数的确定一、最小回流比Rmin本设计为泡点进料，即饱和液体进料，q=1由恩特伍德公式：1)(min,RximDii1iiixq019375.01148.2046875.0148.21705.5015625.01705.5iiix试差法求得2.3则最小回流比304.113.2101.013.2148.27223.0148.23.21705.52677.01705.51)(minimDiixR，二、实际回流比根据混合物分离的难易程度，取实际回流比为最小回流比的1.2倍则R=1.2Rmin=1.2×1.304=1.565组份进料温度133塔顶温度105.5塔底温度136平均相对挥发度苯4.385.9615.1705甲苯1.972.5141.962.148乙苯1111.word教育资料三、全塔理论板数的确定102.01565.1304.1565.11minRRR查《化工原理》下P33图1-28吉利兰图得52.02minNNN将26.6minN代入，求得N=15.2四、进料板的计算5.9lg)()(lg)(HKLKHKLKmRfdfdN3lg)()(lg)(HKLKHKLKmSffN因为SRmSmRRSNNNNNNN)()(2.15，12.112.1535.9135.9)()(1)()(NNNNNNmSmRmSmRR08.412.112.15RSNNN所以,第5层理论板是加料版。3精馏塔主要尺寸的设计3.1塔径的计算3.3.1填料精馏塔有关参数操作回流比：R=2理论板数：NT=16进料板序号：NF=5塔顶温度：tD=105.5℃.word教育资料塔釜温度：tW=136℃3.3.2塔顶有关参数计算[4由化工物性手册查得：3/885mkg苯3/866mkg甲苯3/867mkg乙苯气体平均摩尔质量：molgMV/39.8810601.092722.078268.0气体密度：335/85.22735.10510314.839.8810013.1mkgRTPMDVV液体密度：3/102.87186701.0866722.0885268.0mkgLsmVS/342.085.2360039.8873.393hkmolRDL/4868.262434.1323.3.3进料板有关参数计算smVVSS/342.03,气相组成：94.2m014.0005.0194.21005.094.21xaxy气体平均摩尔质量：molgMV/8.105106986.092014.0'气体密度：335''/71.315.27313310314.88.10510013.1mkgRTPMDVV3'/76101.0771763722.0755268.0mkgL3.3.4精馏段塔径计算液相质量流量为：hkgL/231333.874868.26气相质量流量为：hkgV/75.351139.887.39.word教育资料流动参数为：0377.0102.87185.275.351123135.05.0LVVL由于填料选择的是金属孔板波纹填料350Y；查埃克特通用关联图得：7.02.02LLVmsxgu由于smPaL262.010.1102.8713.958L水0033.0102.87185.2LV257代入上式中得：7.08.90033.010.1262.02max2.0u即：smu/3.3max由于max0.8uu=即：smuu/64.23.38.08.0max由公式muVDS51.064.214.3342.044圆整后为0.6m3.3.5提溜段塔径计算液相质量流量为：hkgL/1709648.6735.253'气相质量流量为：hkgV/42008.1057.39'流动参数为：28.076171.34200170965.05.0''''LVVL同上，查图得：4.02.0''''2'maxLLVgu由于257smPaL207.0'12.1770863'L水00488.076171.3''LV.word教育资料代入上式中得：4.08.9000207.000488.012.12572.02'maxu即：smu/1.3'maxsmuu/48.21.38.08.0max''则：muVDS53.048.214.3342.044'比较精馏段与提溜段计算结果，二者基本相同。圆整塔径，取D=600mm3.4液体喷淋密度及空塔气速核算精馏段液体喷淋密度为hmmDULL2322/58.4423.014.33.7406.23312精馏段空塔气速为：smDuVV/22.126.014.3360085.275.3511222提溜段液体喷淋密度为：hmmU232'/3.3326.014.3420017096提溜段空塔气速为：smDuVV/11.126.014.3360071.34200222'''查规整填料性能参数知32/350mm，取)/(08.023(min)hmmLW则)/(2835008.023(min)(min)hmmLUW经核算，选用塔径600mm符合要求。.word教育资料3.5填料层高度计算填料层高度计算采用理论板当量高度法。对350Y金属孔板波纹填料，由附录查每米填料理论板数为3.5～4块，取：3.5tn=，则：110.293.5tHETPmn===由：HETPNZT精馏段填料层高度为：mZ45.129.05精提溜段填料层高度为：mZ48.329.012提根据设计要求，流出一定的安全系数，填料层高度一般为ZZ)5.12.1('所以mZ885.13.145.1精mZ52.43.148.3提设计取精馏段填料层高度为2.0m，提溜段填料层高度为4.6m。3.6附属设备及主要附件的选型计算一、接管的计算二、（1）塔顶蒸汽管：从塔顶至冷凝器的蒸汽导管，必须适